Signaling system



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lamp panels, and then is automatically retrans-- Patented Oct. -1 7, 1933 UNITED STATES SIGNALING SYSTEM Oscar C. Levy, Chicago, Ill., assignor: by mesne assignments, to Associated Electric Laboratories, Inc., Chicago, Ill., a corporation of Delaware Application September 14, 1929 Serial No. 392,637

9 Claims.

signal from an operated fire alarm box is automatically transmitted to a district office, then automatically relayed to a central supervisors office wherein the signal is displayed on visible mitted to the originating district ofilce, and all other district ofiices, and there displayed on similar lamp pan ls.

A further feature of the invention relates to means whereby visible display signals are indicated in duplicate in order to check the accuracy of the number of the box from which the signal has been received. 1

Other objectsand features of the invention reside in the design of a system utilizing a minimum amount of apparatus in an efiicient manner and to perform all necessary operations automatically. These and other objects and features, not specifically pointed out, will be apparent by referring to the accompanying drawings which together with the detailed description constitute the preferred embodiment of the invention.

The drawings comprising eleven sheets, when laid end to end as indicated in Fig. 12, with their adjoining lines in alignment, diagrammatically illustrate the invention by means of the usual circuit diagrams.

Fig. 1 shows a single fire station FS249 connected to its associated rel 1y equipment RG at a district OfliCBt Fig. 2 shows a sequence switch SS having access to the relay equipment RG of Fig. 1, and also all other fire stations. The sender switch SN sends out the number of the operated fire station. At the upper left-hand corner there is shown a trunk TCl extending to a central supervisors office.

Fig. 3 shows a receiver by the sender SN of Fig. 2.

Fig. 4 comprises a digit storage relay group DS3 and their associated contacts which control a group of lamps arranged in a lamp panel.

Exceptior the fire alarm station FS-249, Figs. 1,2, 3, and 4 comprise all the equipment associated with a single district ofi'ice. I

Fig. 5 shows various lamps and keys associated switch R2, controlled with the equipment at the central ofilce or supervisors position, together with a group of relays connecting the supervisors position over a trunk line ,TC-2 with the district ofiice.

Fig. 6shows a finder switch F, for seizing the line extending from the district ofiice. The lower part of the figure shows a transmitter switch T, individual to the district ofiice, for transmitting the number of the fire alarm box which is operated.

Fig. '7 shows the receiver switch R--1, which receives the number of the line with which the finder Fof Fig. 6 isassociated.

Fig. 8 illustrates a set of digit storage relays DS2 connected to a lamp panel which displays 7 the number of the operated fire alarm box.

Fig. 9 shows the code sender-switch CS for translating the code of the operated fire alarm station so as to operate the punch, register PR.

Fig. 10 illustrates the control relay group CR and associated relays and also the operators calling device key set CD, for manually setting up numbers received over still alarms or telephone systems to control the digit storage relays of Fig. ,8.

Fig. 11 diagrammatically shows the general layout of the complete system as shown in detail on the other drawings.

Fig. 12 shows a general layout of the method of connecting together the difierent sheets of drawings.

Fig. 13 is a code chart illustrating the orderv in which the digit storage relays of Fig. 8 and Fig. I 4 operate and display a number on the lamp panel.

Referring now particularly to Fig. 11, this drawing diagrammatically illustrates the principles involved in the invention. In the lower right-hand corner there is indicated a central supervisors position having branch lines associated with a number of district ofiices of whichtwo are indicated. Each district ofiice, for example No. 1, has a large number of firealarm boxes, or stations connected to it, all of which are in a particular district or area under control of this oflice. Each fire station for example FS 249, is connected with the ofiice over a normally closed circuit. Each line has associated with it at the district otfice, a pair of lamps, one lamp to indicate when an alarm is sounded, and the other to indicate when there is a case of trouble on the line, such as a broken down line or a grounded line. Each district ofiice is equipped with a display panel and has means wherein the operation of a fire alarm box sets in operation certain equipment in the ofiice to seize a trunk line extending to the supervisors position. The supervisors position is equipped with a number of keys and lamps, one such set being shown as connected to the district oifice No. 1, and also a display panel similar to that in the district oflice.

In the operation of the system when a fire alarm box, such as FS--249, is operated, the associated alarm lamp is illuminated at the district ofiice No. 1 and equipment at the district oflice seizes this line and extends this to the supervisors position where another alarm lamp is illuminated indicating that the alarm is coming from this particular district ofiice. Equipment at the super- ,visors position then is set in operation to automatically translate the number of the box and display it on a lamp panel in duplicate, in orderto insure that the correct number has been set up. This number is then retransmitted back to the district oflice in which the call originated and there displayed on a similar lamp -panel in duplicate. This number is also sent out by the equipment to all other district ofiices, terminating in the supervisors position, so that they will be aware of a fire and know the location ofit. It will be noted that the only action required is to merely open the fire alarm line extending -from the fire box to the district office and to set up the number inthe supervisors position and to operate all of the equipment.

Facilities are provided whereby still alarms may be received over a telephone line at the supervisors position and there set up on display panels of the position; and. also transmitted to each of the district offices. Other facilities provide for connection at the fire alarm box, with the telephone line extending over the fire alarm trunks to the district office and thence to the supervisors position.

All of the switches disclosed in this invention are of the same general type wherein the wipers are rotated in a forward direction over their associated bank contacts under the influence of a stepping magnet. The. direction of rotation of each wiper is indicated on the drawings. Each time this magnet becomes deenergized it advances the switch wipers one step over the bank contacts. A switch of this general type is disclosed in Patent No. 1,693,027, issiied November 27th, 1928 to John Erickson.

A detailed description of a regular fire alarm call will now be given. The fire alarm'station shown in Fig. 1 and designated FS-249 may be of any well known type of construction such as f the break glass type or otherwise, wherein a handle is turned and this operates to momentarily open the contacts 5 which are normally closed. Relay 40 and high resistance relay 30 at the district ofiice are normally energized over the line conductors 2 and 3, and through the normally-closed contacts 5. The high resistance shunt 6 is normally shunted out by the contact 5, so that opening the line conductors 2 and 3 at the contact 5 inserts the high resistance 6 across the line. As a result of this relay 40 being of low resistance deenergizes, while relay 30, being of very high resistance, remains energized in series with the shunt 6.

- Relay 40 upon deeiiergizing, at the back contact of armature 41, places ground through the fire alarm lamp AL, through the winding of relay 25 to battery. Relay 25 at armature 2Q closes a circuit for the audible,alarm signal SG. The

ringing of the signal SG informs an attendant at the station house that an alarm has been sent in while illumination of the lamp AL indicates \operates the contacts 211 it deenergizes,

the particular fire station or location from which the alarm has been sent. At the back contact of armature 41 ground also extends by way of armature 32 and its front contact through the winding of relay 20 and the resistance to battery. Relay 20 upon operating closes a locking circuit for itself extending from ground on armature 23, and its front contact, armature 32 and its front contact, to relay 20. A branch of this circuit extends to the lamp AL so that it remains lighted when relay 40 again energizes due to contacts 5 closing. At front contact of armature 22 a circuit is prepared extending over to conductor 50, while at the front contact of armature 21 a circuit is prepared extending over conductor 51 for the relay 10. 1

At the front contact of armature 24, relay 20 grounds the start conductor 247 which is common to all the other relay groups RG associated with all the fire alarm stations connected to this district station. This ground extends over conductor 247, through Fig. 4 and Fig. 3, back contact and armature 301, back contact and armature 231 of relay 230, through the winding of relay 200, to battery in the sequence switch SS. Relay 200 upon energizing, operates its armature 201 and places ground to its front contact, through the winding of relay 205, back contact and armature 211, through-the winding of rotary magnet 210,

this circuit. At the front contact of armature 202 the test wiper 215 is connected to a point between the stepping magnet 210 and relay 205. The bank contacts of the wiper 215 connect to the various relay groups RG associated with all the fire alarm lines in this district, only one of which has been shown connected. All the lines not equipped 'have their contacts permanently grounded. Ground, therefore, extends from the bankbcontact upon which wiper 215 is resting through wiper 215, armature 202 and its front contact, to the junction point of relay 205. The other side of this relay is also grounded at armature .201, and it, therefore, is short-circuited. A branch of this circuit extends through armature 211, through the winding of stepping magnet 210, to battery. Magnet 210 energizes and when it and rotatesthe wipers 215 and 216 on to their first set of bank contacts. The first contact in the bank of wiper 215 extends to a relay group similar to RG and over a similar conductor 50-to ground, at armature 23 of relay 20 of this other relay group. This ground, therefore, extends back over wiper 215 to again energize the magnet 210 and set the wipers onto the next set of bank contacts. This action continues until the fifth bankcontact is reached to which the conductor 50 is connected. In this case the relay 20 has operated to remove the ground from its armature 23 extending over conductor50 and substituted, therefore, the battery from the relay 20 extending through its front contact and armature 22. Relay 205 is, therefore, no longer short-circuited, but is energized from ground on armature 201 through the relay 205 and then through the winding of stepping magnet 210, to battery. Themagnet 210 does not operate in series with relay 205, and the stepping operation of the sequence switch SS is halted, and it remains in its operated position.

At the front contact of armature 206, relay 205 places ground through wiper 216, the fifth contact upon which it is now resting, conductor 51, armature 21 and its front contact, through the winding of relay 10, to battery. Relay 10 upon operating, places ground on all of its armatures, thereby connecting ground on each of the conductors 60, 61, 62, 63, and 64, extending through the cross connecting block CB to the bank contacts of the sender SN. The cross connecting block CB is provided ,so that additional fire alarm stations may be connected up, or existing ones removed or changed. The right-hand terminals of the connecting block are connected to other relay groups such as RG, associated with other fire alarm lines under the supervision of this particular district station. These conductors at the terminals are all cross-connected to the left-hand terminals of the block CB in accordance with the number of the fire alarm box. The cross-connection of the wires at the terminal block CB and the connection to the bank contacts of. the wiper 270 of the sender S determines the code which is tobetransmitted and which is associated with each individual fire alarm. line or box, there being one box per line. At the front contact of armature 203 relay 200 places ground on this armature"- through the winding of relay 220, to battery. Relay 220 upon energizing at the back contact of armature 222 opens a point in the circuit of relay 240 and at the back contact of armature 221.

ground is removed from the bank contact of wiper 2'71 and extended to the front contact of this armature through the winding of relay 290, to battery;

Relay 290 is associated with the group of relays comprising the trunk circuit TC1, controlling the trunk line comprising conductors 233 and 234'which extends from the district station to the supervisors office. At armatures 291 and 293, relay 290 transfers the trunk circuit from its back contacts to the front contacts. At the front contact of armature 292 ground is extended through the winding of relay 280 to battery. At the back contact of armatures 281 and 282 of relay 280, relay 285'is removed from the line conductors 233 and 234 over which it has been previously held energized. At the front contacts of these armatures, the trunk line is extended to the armatures 291 and 293 of relay 290. At front contact and armature 283 the battery through the resistance is connected to armature 294 but that contact is now open and this is without effect. I .As a result of the deenergization of relay 285 its armatures retract, and at armature 287 and its back contact ground is placed through the lamp TCL,- to battery, indicating to an attendant at the district station that the trunks 233 and 234 extending to the supervisor's position have been seized. 0

After the trunk line' conductors 233 and 234 have been seized by the apparatus at the district station and extended to the supervisors position they must be placed in such condition as to receive the number of the fire alarm box that is operated. The trunk lines 233 and 234 terminate in Fig.5 at the supervisor's position in a pair of relays 500 and 505 in the trunk circuit TC-2. Relay 500 is connected to the lower conductor 234 over armatures 512 and 518 and relay 505 is connected t0 conductor 233 over armatures 511 and 517. These relays have been normally energized over the trunk line in series with relay 285 of the trunk circuit TC1. At the time relay 280 operated its armatures 281 and 282, it disconnected-relay 285 from the linefconductors and I thereby permitted relays 500 and 505 to be de- "energized. At armature 501 and its back contact I relay 500 placesground through 'the lamp TL.

opens the ground circuit from its armature 506v and removes the ground from conductor 540 extending to the bank contact of the finder switch F, in order to mark this trunk in the bank of the finder. Armature 507 closes at its back contact, places ground on the conductor .544extending to Fig. 6', and through the winding on relay 600, to battery at the finder F.

All of the trunk lines such as TC-2 for example, which are not in use at the present time and are all extended to the bank contacts over which wiper 616 rotate, will have ground placed on them similar to that shown at armature 506. All other trunk, lines not equipped or not in use will have their bank'contacts permanently grounded. In the instant case the bank contact to which conductor 540 is attached will have ground removed from it at armature 506. At the time relay 600 is operated it closes its front contact on armature 601 and completes a circuit extending from.

ground on the last bank contact upon which wiper 616 is resting to wiper 616, armature 601 and its front contact, back contact and armature 614, through. the winding ofstepping magnet 615 to battery. Magnet 615 operates and at the back contact of armature 614 opens its own circuit, and when it deenergizes it advances the wipers 616, 617, 618, and 619 on to the first set of bank contacts. As/this set of bank contacts is connected to a trunk not in use at this time, there will be ground fed to wiper 616 and the magnet 615 will again be energized to interrupt its own circuit and upon deenergizing advance the wipers an-] other step. This action continues as long as the wiper 616 rests on bank contacts which are grounded. When the fifth bank contact is reached to which conductor 540 is attached, there will be no ground on this contact, and consequently, the operation of the rotary magnet is stopped.

At the time relay 600 operated, it closed its armature 602 from ground to its front contact,

through armature 606 and its back contact, then through the winding of slow-release relay 610, to battery. When slow-release relay 610 has oper-'- ated, it completes a circuit extending fromground on armature 611 and its front contact through the winding of slow-operating relay 605 to the junction point between the stepping magnet 615 and the wiper 616. At the time the rotary magnet v615 was operating, and the wiper 616 was rotating over the bank contacts, relay 605 was short-circuited on one side of its winding from armature I 611 and on the other side from ground and the bank contact over which wiper 616 is rotating. Relay 605 is of such high resistance that stepping magnet 615 cannot operate in series with it when the wiper 616 reaches the bank contact upon which conductor 540 is attached. There will be no ground in this conductor and the rotation of the switch is stopped. Consequently, the relay 605 energizes in series with the stepping magnet 615.

When relay 610 operated, it closed its armature 612 on the front contact to close a pointin the circuit of wiper 618, and at armature'613 opens a point in the circuit of wiper operating relay 605 energized it moveelits arma ture 606 from its back contact to its front con- 619. When slowtact, thereby completing a locking circuit for it self extending from ground on armature 602 and its front contact, armature 606 and its locking contact, through the winding of relay 605, then to armature 614, through the winding of relay 615 to battery. At the back contact of armature 606 the circuit for relay 610 is interrupted, and this relay slowly restores its armatures. At armatures 608 and 609 relay 605 switches the trunk through to the receiver R-1 in Fig. 7. At the front contact of armature 607, it completes a circuit extending from ground on armature .602 and its front contact, front contact and armature 60'7, armature 603 and its front contact, conductor 545, through Fig. 5, then down to Fig. 10, through the winding of relay 1005, to battery. Relay 1005 energizes and at armature 1009 and its front contact completes a locking circuit for itself extending from ground on armature 1021 of relay 1020 through armature 1009 and its front contact. Relay 1005 remains locked in position for a purpose which will be later on explained.

At the time relay 605 is energized, it also closes armature 604 on its front contact and places ground over conductor 6'70'to Fig. '7, through the winding of relay '700 to battery. Relay 700, therefore, energizes and at armature 701 places ground on its front contact over a circuit extending through armature '711 and its back contact, conductor 6'74, wiper 617 and the fifth bank contact of this wiper to which conductor 541 is connected, through the winding of relay 510 to battery. A branch of this circuit extends through the lamp EL to battery. The illumination of the lamp indicates to the supervisor that the transmission of the number of the fire alarm station is about to begin. Relay 510 at armatures 511 and 512 switches the trunk conductors onto the front contacts, and at armature 513 holds open the circuit of relay 515.

As a result of the switching through of the trunk cond'uctors 233 and 234, a circuit is momentarily completed extending from ground on armature 602 and its front contact, front contact and armature 60'7, armature 612 and its front contact (this is a momentary impulse and occurs before relay 610 has a chance to fall back and restore its armatures), wiper 618 and the fifth bank contact upon which it is now resting, conductor 542, front contact and armature 511, in the trunk circuit TC--2, back contact and armature 51'7, upper trunk conductor 233, armature 281 and its front contact, in the trunk circuit TC-1, armature 291 and its front contact, back contact and armature 241 of relay then through the winding of relay 235 to battery. Accordingly, relay 235 energizes, and at its front contact and armature 236 completes a locking circuit for itself extending from battery through the winding of relay 235, armature 236 and its front contact, winding of relay 240, back contact of armature 232, to ground. Relays 235 and 240 are, therefore, held energized in series when the ground pulse is removed from the line at armature 612. At the back contact of armature 241, relay 240 opens the original energizing circuit of relay 235.

At the front contact of armature 243, a circuit is prepared extending over the lower trunk conductor 234 for transmitting impulses from the sender switch SN and at the front contact of armature 242 ground is extended through armature 251 and its back contact, armature 261 and its back contact, back contact and armature 252, through the winding of relay 245 to battery, around the high resistance shunt. Relay 245 240, in the sender SN,

upon energizing, operates its armature 246 and connects ground to its front contact, armature 253 and its back contact, through the winding of the stepping magnet 260 to battery. A branch of this circuit also extends from ground on armature 246 to its front contact, front contact and armature 243, front contact and armature 293 of relay 290, through the compensating resistance, front contact and armature 282, trunk conductor 234, Fig. 5, armature 518 and its back contact, armature 512 and its front contact, conductor 543, the fifth bank contact of the finder F upon which wiper 619 is now resting, back contact and armature 613, front contact and armature 609, conductor 673 to Fig. '7, to the winding of relay 740 to battery.

Relay 740 will respond to impulses received over this circuit from armature 246. Each time the stepping magnet 260 energizes, it opens the back Contact of its armature 261, thereby opening the energizing circuit of relay 245. Relay 245 upon falling back, at armature 246 opens the circuit of .stepping magnet 260, and this magnet, each time upon restoring, advances the sender switch wipers 2'70,2'71, and 272 in a forward direction over their associated set of bank contacts. Wipers 2'71 and 272 are without effect at this time, but wiper 270 which is now standing on the first bank contact completes a circuit extending from ground on the first armature of relay 10, through the cross-connecting block CB, conductor 60, first bank contact of the sender SN, wiper 270, front Contact and armature 291, front contact and armature 281, upper trunk conductor 233 extending to Fig. 5, armature 517 and its. back contact, armature 511 and its front contact, conductor 542 connected to the fifth bank contact upon which wiper 618 of the finder F is now' resting, front contact and armature 608, conductor 672 to a junction point between the wipers '761 and 762 of the receiver R-1 in Fig. '7. Each time wiper 2'70- picks up ground at its bank contacts, it transmits this ground to the wipers '761 and 762. As soon as the stepping magnet 260 deenergizes, it again closes the circuit for relay 245 which at its armature 246 again extends ground to the stepping magnet 260 and also to relay 740. This interaction between magnet 260 and relay 245 continues for a time as will be further explained.

The wipers 2'70, 271, and 272 are, therefore, continuously advanced over their bank contacts in a forward direction, and as wiper 2'70 encounters the bank contacts to which conductors 61, 62, 63, and 64 areconnected, ground then will be extended over this wiper from the cross-connecting block CB and the which. are all operated. It will thus be seen that each time relay 245 is energized it transmits a ground pulse over the lower trunk conductor 234, to the receiver switch R1 and the relay 740, energizing and deenergizing this relay alternately. Likewise each time -that the wiper 2'70 encounters one of the grounded bank contacts, it will transmit a ground from the armatures of relay 10 over the upper trunk conductor 233, to

Fig. 7 and the junction points between the wipers '761 and 762.

Referring now to the operation of receiver R--1 of Fig. '7, as relay '740 is alternately energized and deenergized from ground over the armatures of relay 10 lower line conductor, it opens and closes the ground at the front contact of armature 741, through the back contact of armature '731 of relay 730, then over two parallel paths to armature and back contact '732, armature 751 and its stepmagnet 750 energizes and when relay 740 falls back it opens its armature spring 741 from the ground thereby permitting the stepping magnet 750 to deenergize. The wipers 760 to 764 inclusive, of the receiver R-l are, therefore, advanced one step. Wiper 764 steps on to its first bank contact but without closing any circuit due to the fact that the circuit is open at the armature 701 which is operated by relay 700.

Wipers 760, 761, and 763, it will be noted, are

,now standing on the .last one of their bank contacts, while wipers 762 and 764 are resting on their first set of bank contacts. Therefore, when wipers 762 and 764 have advanced one revolution around the set 'of bank contacts they are resting on the last contact while wipers 760, 761, and 763 will be in a position opposite their first set of bank contacts. Therefore, it requires steps or 360 degrees to make one full revolution and return the wipers to their normal position. Wiper 762 is at present operated and resting on its first bank contact at this time, and the sender SN of Fig. 2 has also advanced the wipers on the first set of bank contacts so that wiper 270 is now resting on the bank contact connected to conductor and this conductor has been grounded by relay '10 in Fig. 1. Consequently, this ground is extended over the line conductor; 233, as has been pointed out, and conductor 672, to the junction points between wipers 761 and 762, down through wiper 762 and the first bank contact upon which it is now resting, conductor 770 to Fig. 8, then through the winding of the relay 800 to battery, in the first digit relay group Sl.

As soon as relay 800 energizes, it completes a locking circuit for itself through its front contact and armature 801, to ground over a circuit extending over conductor 558 to Fig. 9, to the back contact of armature 1021 to ground at relay 1020 of Fig. 10. When the wiper 762 steps onto the next bank contact, this ground is removed from relay 800 but it remains locked in its energized condition. The next time relay 740 energized and deenergized, the stepping magnet 750 advanced the wipers 760 to 764 to the second set of bank contacts. At this time, however, no circuit is completed through the wiper 762 over conductor" 672 from the sender SN and its wiper 270, because this wiper is now resting on a bank contact to which a conductor is attached, which has not become grounded by relay 10. Consequently, the digit storage. relay B of the group S1 in Fig. 8, will not be energized. However, when wiper 270 reaches the third bankcontact and wiper 762 of Fig. 7 also reaches its third bank contact, ground will be sent over the circuit from conductor 61 through the wiper 762, conductor 772, through the winding of the digit storage relay 820 to battery. At armature 821 and its front contact, relay 820 looks itself to the conductor 558. This simultaneous and synchronous operation of the sender switch SN of Fig. 2 and the receiver switch R. 1 of Fig. 7, continues and each time the wiper 270 encounters a bank contactwhich is grounded by one of the conductors 60, 61, 62, 63, and 64 which corresponds to the code number of the operated fire alarm box, this ground is transmitted through wiper 762, and the conductors "770, 772, 776, 777, and 782 have each become grounded and have consequently, operated relays 800 and 820 of the group S1 for the first digit of the number of the fire alarm box, relays 840 and 850 of the group S2 for the second digit, and relay 860 of group- S3 for the third digit.. Each of these relays remain energized and locked to conductor 558 after the ground has been. removed from wiper 762.

Referring now to Fig. 13, this represents a code chart diagram illustrating the numbers displayed whenever any of the relays A, B, C, and D of the groups Sl, S 2, and S-3 are operated in combination. It will be noted that .when relays A andv C of a group are energized and operate their armatures, the digit two' will be displayed on the lamp panel. When relays B and D are energized, the.digit four will be illuminated on'the lamp panel, and likewise, when the relay C is energized, the numeral nine will show up on the lamp panel.

Referring to the circuit of Fig.8, it will be remembered that-relays 800 and 820 are held energized and, therefore, a circuit is closed from ground on armature 802 and its front contact, armature 812 and its back contact, armature 822 and its front contact, through the lamp number 2,. through to battery. Therefore, the numeral 2 will be displayed at the supervisor's position. These lamps it will be understood, will be arranged in a regular lamp panel so that all displayed numerals will be in consecutive order in three different groups Sl, S2, and S3.

This operated lamp number 2 constitutes the first digit of the code number. i As relays 840 and 850 of'group S2 have been energized, it will be observed by referring to the Fig. 13, that the lamp number 4 will be illuminated, from ground on armature 841 and its back contact, armature 842 and its front contact, armature 843 and its front contact, through lamp 4, to battery. In the third set of relays S3, relay 860 isoperated and consequently digit 9 is displayed, over a circuit from ground on armature 861 and its back contact, armature 862 and its back contact, armature 863 and its front contact, armature 864 and its back contact to lamp, 9, to battery. The complete number 249 of the fire station which is operated will, therefore, be displayed before the supervisor and appraise him of the existence of a fire at this particular fire alarm box.

Returning now to the operation of the receiver R-1 of Fig. 7, and the sender SN of Fig. 2. these switches after having .set up the numbers on the display panels DS-1 continue to advance their wipers in a forward direction under control of their respective stepping magnets. When the wiper 271 has advanced until it has encountered bank contact 274, it completes a circuit extending from ground multipled through all the remaining bank contacts after contact 274,

opens the circuit extending to the stepping magnet '260. At the back contact and armature 252 it interrupts the circuit of relay 245 and this relay restores armature 246. At armature 251, relay 250 opens a. further point in the circuit of relay 245. When relay 255 became energized it closed armature 257 upon its front contact, com-' pleting a circuit extending from ground on the bank contact 274, wiper 271, front contact and armature 257, armature 261 and its back contact, front contact and armature 259, then through the winding of thestepping magnet 260, to battery. 3

' been previously when the fire Relay 255 closes the front contacts on armatures 258 and 254 without effect at this time. Consequently, the stepping magnet is again energized. Upon energizing it opens its armature 261 to interrupt its own energizing circuit so that it is now self-interrupting and continues to operate as long as wiper 271 rotates over grounded bank contacts. Wipers 270, 271, and 272 are, therefore, further stepped in a forward direction over their bank contacts. During this stepping interval,

however, no further impulses are sent over the- Fig. 2 will be resting at the same time on bank' contact 274; the switches, it will be observed having advanced the same number their associated bank contacts. The wiper 764 resting on bank contact 766 will have ground connected to it in multiple through all the remaining bank contacts, through the winding of slow-to-release relay 720, to battery. Relay 720 energizes and at armature 722 and its front contact connects ground through the winding of relay 730 to battery. At armature 723, relay 720 prepares the automatic stepping circuit of the magnet 750. At armatures 731 and 732, relay 730 opens the circuit which originally en.rgizes the rotary magnet 750. The energizing circuit for this magnet is now completed over wiper 764 from the grounded bank contacts through armature 723 and its front contact, then through the back contact and armature 751, through the winding of stepping magnet 750, to battery. Each time this magnet energizes it interrupts its own circuit at armature 751 and it falls back. thereby further advancing the wipers 760 to 764, inclusive, over their bank contacts. When the wiper 764 reaches its last bank contact 767, the stepping operation is momentarily halted, due to the absence of ground on this contact.

In the sender SN, when the wiper 271 reaches the bank contact 2'76, there will be no ground on this contact, and the stepping magnet 260 no longer operates. Slow-acting relay 255 likewise has its circuit interrupted at this point and it deenergizes, restoring all of its armatures.- At armature 256, it opens the circuit of relay 250 and allows it to fall back and this restores its armatures 251, 252, and 253. At armature 259 relay 255 opens the self-interrupting circuit of the stepping magnet 260. The circuit of the sender SN is now in the same condition as it had alarm signal first came in, and when the sender was at normal, likewise, in the receiver R1 of Fig. 7 a similar action has taken place. When wiper 764- reaches the bank contact 767 ground will no longer be transmitted through the wiper 764 to hold up re-v lay 720, and a branch of this circuit to operate stepping magnet 750. Consequently, relay 720 slowly deenergizes. This relay is so adjusted and arranged that it will restore its armatures beforethe slow-release relay 255 of sender SN, in order to keep these switches in synchronism. At this time, it will be observed, that the'wiper 2720f the sender is positioned opposite the first contact inthe bank instead of the last one as it was causing of steps over in its normal position; also in the receiver 3-1, the wipers 760, 761, and 763 will be positioned opposite their-first set-of bank contacts instead of the last set and the wipers 762 and 764 will be positioned one step away from their last set of bank contacts. The sender SN of Fig. 2 is again operated as it had been in the first instance. to send out the same code number to the receiver R-1 and control its operation. The wipers 270, 271, and 272 are again advanced in a forward direction over their bank contacts due to the action of the stepping magnet 260. Each time that relay 245 energizes it sends a ground pulse from armature 246 and its front contact-over conductor 234, through the winding of relay 740 of the receiver R-1, to battery. Accordingly, relay 740 again follows the energization and deenergization of the relay 245 the stepping magnet 750 to advance the wipers 760 to 764 over their bank contacts in a forward direction as has been described before. The wiper 270 of the sender SN also rotates over its bank contacts and picks up the ground from conductors 60, 61, 62,63, and 64 from the operated relay 10 and transmits these grounded pulses over the upper line conductor 233 to the junction point between wipers 761 and 762; but in this instance, however, instead of being transmitted through the wiper 762 which is now rotating away from the bank contacts, they will be transmitted through the wiper 761 and its bank contacts upon which it is now rotating. These bank contacts are connected to a second digit storage relay group DS--2 to which similar equipment is connected, as that shown in Fig. 8. In a similar manner as before, these relays such as 810 and 820 for the first digit; 840 and 850 for the second digit, and 860 for the third digit, are energized so that these relays operate and display the number 249 of the fire alarm box in a similar manner as had been done on the first lamp panel. This lamp panel is a duplicate of the first and arranged immediately above it and the duplicate transmission is an indication to the supervisor at the desk that the correct signal has been received. If a different number is displayed on the second digit storage relay group DS-2 from that which has been shown on the first one DS-l. he will know that there has been an error somewhere, or that the equipment is not functioning properly.

When wiper 271 reaches its bank contact 274, it again completes the circ t through the winding of slow-release relay 255. This relay upon energizing closes its armature 256 and completes the circuit for relay 250. Relay 250 operates its armatures and allows relay 245 to be deenergized and opens its armature 246 so that no further ground pulses will be sent over the trunk line, to operate the relay 740 in Fig. 7, and-so that the sender SN will have no further control over the receiver R--1. Relay 255 at its armature 257 completes a circuit from ground at bank contact 274, wiper 271, front contact and armature 257, armature 261 and its back contact, front contact and armature 259, through the winding of the stepping magnet 260, to battery. At armature. 261, magnet 260 interrupts its own circuit, and further operates the wipers 270, 271, and 272 until wiper 271 reaches its bank contact 276 upon 1 which there is no ground. Accordingly, relay 255 deenergizes and prevents further rotation of the switch, which is now in its initial normal position. Previous to this, however,'the wiper 272 engaged the bank contact 275, and it completed a circuit extending from ground on wiper 272, bank contact 275 is multiple with all remaining bank contacts, armature 254and its front contact, through the winding of slow-release relay 225, to battery. This relay energizes for a purpose which will be explained later on.

In the receiver R-l of Fig. 7, the stepping magnet 750 has been alternately energized and deenergized, during this period, over the circuit extending from ground on bank contact 765, wiper 763, through the winding of slow-release relay 720, to battery. This relay energizes as before and completes a circuit at armature 722 for relay 730 which operates its armatures 731 and 732 to remove the control of the stepping magnet 750 from the relay 740. 723 and its front contact, relay 720 completes the self-interrupting circuit for the stepping magnet- 750. Ground is now extended from grounded bank contacts 765 through which the wiper 763 is rotating, armature 723 and its front contact, back contact and armature 751, through the winding of the stepping magnet 750, to battery. The stepping magnet interrupts its own circuit to step the wipers 760 to 764, inclusive, further over their bank contacts. When wiper 763, reaches its bank contact 769 no further ground is available for the stepping magnet 750. Accordingly, this magnet deenergizes, Slow-release relay 720 likewise falls back slowly and at its armature 722 opens the circuit of relay 730 which restores its armatures. However, before relay 720, which is slow to release, completely restores its armatures, a circuit is completed extending from the grounded contact upon which wiper 760 is now resting, armature 721 and its front contact, through the winding of relay 710, which is slow to release, to battery. Relay 710 energizes and opens its armature 711. Another branch of this ground circuit extends over conductor 547 throughFig. 6, through the contact 560 of the automatic transmission key AT, Fig. 5, over conductor 554 to a junction on one side of the -circuit extending to armature 1007 and its front contact of relay 1005, which it will be remembered was locked energized, through 'the ,winding of relay 1010, to battery. The other junction extends through the code senderfCS of Fig. 9,

over conduct r 554, through thewinding of relay 930, to. attery. This is in order to start the operation of the code sender CS, which switch is arranged to translate the code number set up on the digit storage relay group DS-l of Fig. 8, and translate this into numerical digits which are suitable for operating the punch register PR, as will hereinafter be explained.

After relay 930 of code sender CS and relay 1010 of Fig. 10 are energized, relay 720 of Fig. 7 has completely released its armatures, andat front contact and armature 721 opens the original circuit of relay 710, but this relay remains held up over its other circuit. When relay 7 10 energized'at its back ,contact arid armature 711, it opened a circuit extending from ground on armature 701 and itsfront contact, armature 711 and its back contact, conductor 674, wiper 617 of the finder F, conductor 541 to the relay 510 of the trunk circuit TC2, to battery. Relay 510 falls back and disconnects the trunk conductors. 542 and 543 from itsarmatures 511 and 512. At armature 513, it closes the circuit of relay 515 and.thisfrelay energizes from ground on armature 1006, Fig. 10, conductor 556 which is conirnon, back contactand armature 513, through th winding of relay 515, to battery. Relay 515,

At armature upon energizing switches the trunk conductors 233 and 234 to the conductors 546 and 550. 'At the front contact of armature 516 it places ground on relay 505, permitting this relay to again energize, so that at its armature 507 it removes ground from its back contact which was previously extended over conductor 544 to relay 600 of the finder F. Accordingly, relay 600 deenergizes and at grounded armature 602 and its front contact it opens the locking circuit for relay 605, and this relay deener'gizes and releases its armatures. At armatures 608 and 609, relay 605 opens the trunk extending to receiver R.l in Fig. 7. Relay 740, therefore, deenergizes. The release of the sender SN, the finder F, and the receiver R-1, has now taken place. The trunk circuits TCI and TC2 are also now in conditionfor retransmitting the received number.

The system has now been operated to receive the fire alarm number and display it in duplicate at the supervisors position. The action which is now to take place is for the transmitter T, Fig. 6, to be operated, and the code sender CS in Fig. 9 to operate the printing register PR, so as to leave a permanent indication of the number of the fire alarm box which has been operated. The transmitter operates to send out impulses over the trunk circuit extending to the originating district station represented by Figs. 1, 2, 3, and 4, and to transmit these pulses into the receiver R-2 of Fig. 3, and operate the digit storage relay group of Fig. 4, to display thenumber of the operated fire alarm box at this district station which is the station connected to the particular alarm box which has sent in the alarm. In addition to the .v

transmitter T, which is individual to the trunk extending to this particular district office, the other transmitters connected to the multiple conductors in the bank of wiper 665, transmit this same fire alarm number to all the other district stations connected to the supervisors position,-

and operate receivers similar to R2 of Fig. 3 and there display the numerals of the operated fire alarm box. This is to appraise all. fire engine companies at the district ofiice controlled by the supervisors position, that that particular box has been operated and they will know from the number displayed, whether they are or are not required to respond to this fire call. The transmission of the number back to the originating district oiiice is an indication to the attendant at this oifice that the signal has been properly transmitted to the supervisors ofiice and has also been properly transmitted back to the dis- It will be remembered, that when the sender SN had completed its operation and the-wiper 272 is at its normal position, the relay 225 was operated. At is armature 228 it placesgroundover its front contact to energize relay 230, and at its front contact and armature 227 closes a locking circuit for itself extending over conductor 238 to ground on the front contact of armature w 302. Relay 230 at its back contact and armature 232 removes ground from relay 240 which was held energized in series with relay 235. ,.These two relays, accordingly, release and restore their armatures. At the back contact of armature 231, relay 230 opens the circuit extending over the start conductor 237 to relay 200 of the sequence switch SS, thereby permitting this relay to restore. At the front contact and armature 201 relay 200 opens a circuit of relay 205 and this relay upon restoring removes ground from the front contact of armature 206 extending over lE J ' tacts of the sender SN. At the front contact of armature 203, relay 200 removes ground fromthe circuit of relay 220 so that this relay likewise restores. At the front contact of armature 221 relay 220 removes ground from the circuit of relay 290 and this relay then restores to normal, thereby closing the line conductors 233 and 234 on its back contacts 291 and 293, so as to connect the trunk with the receiver R2 of Fig. 3 preparatory to receiving the impulses sent over this trunk from the transmitter T. At the front contact of armature 292, relay 290 opens a point in the circuit of relay 280, but its circuit is maintained through the back contact and armature 286 of relay 285, over conductor 284, to Fig.3 and to the back. contact and grounded armature 316 of relay 315.

It willbe remembered, that the relays of the storage relay group DS-l of Fig. 8, had been energized and were held locked up to their own locking contacts to conductor 558, which maintains ground for these relays and also on conductors 7'70, 772, 7'76, 777, and 782. The operation of the transmitter- T and its control over the receiver R2 of Fig. 3 is somewhat similar to the operation of sender SN-which controlled the receiver R*1. This will now be explained. At the time relay 1010 of Fig. 10 was operated due to its circuit being closed from the wiper 160 in Fig. 7, it placed ground on its front contact and armature 1011 over conductor 549 through Fig.

5, through the winding of relay 655 of the transmitter T, to battery. Relay 655 upon operating at armature 658,, places ground on its front contact through the winding of relay 650 to battery. Armatures 656 and 657 are without effect at this time. Relay0 is slow to operate'and, therefore, relay 655 closes a circuit extending from battery and resistance on armature 659 and its front contact, back contact and armature 651, conductor 550 wh ch is common to all other trunk circuits TC2, front contact and armature 518, trunk conductor 234, armature 282 and its front contact, trunk compensating resistance, armature 293 and its back contact, conductor 244 of Fig. 3, armature 311 and its back contact, through the winding of relay 305, then over to back contact and'armature 316 of relay'315 to ground. Consequently, relay 305 received a momentary impulse before relay 6500f the transmitter is fully operated. Relay 305 upon operating, closes a locking circuit for itself at its front contact and armature 306 in series with relay 310 to battery, and the ground on armature 316. This starts to prepare the operation'of the receiver.

Relay 650, has during this interval, become operated and at its grounded front contact and armature 652 completes a circuit extending to slow-to-operate relay 635, and after a short interval this operates its armature 636 to its front contact. This completes a circuit which extends from ground on armature 1011 of relay 1010 over conductor 549 and which ground also energizes relay 655, and transfers this ground through armature 636 and its front contact, back contact and armature 626 of relay 625, back contact and armature 661 of the stepping magnet 660, armature 62'? and its back contact, "through the winding of relay 630 to battery, and around the shunt resistance of this relay. Relay 630 upon operating, closes ground from its front contact to armature 631, back contact and armature 628, through the winding of the stepping magnet 660, to battery. Upon operating, stepping magnet 660 opens its armature 661 from its back contact, thereby interrupting the circuit of the relay 630 which falls back and opens its front contact and armature 631 to deenergize the stepping magnet 650. The relay 630, and the stepping magnet 660, therefore, alternately energize and deenergize each other, and the stepping magnet rotates the wipers 665, 666, and 667 in a forward direction over their bank contacts, each time it is deenergized. Each time the relay 630 energizes it also places ground to its front contact and armature 631, over another circuit extending through back contact and armature 647, front contact and armature 651, conductor 550, front contact and armature 518, over the lower trunk conductor 234, armature 282 and its front contact, armature 293- and its back contact, conductor 244, armature 311 and its front contact *on relay 310, armature 324 and its back contact, through the winding of relay 325, to battery. Relay 325, therefore, operates and follows the impulsesdelivered to it from ground on armature 631 of relay 630. When relay 325 operates it places ground over a circuit from armature 326 and its front contact, armature 331 and its back contact, back contact and armature 332, through the winding of the stepping magnet 340 to battery. Each time the stepping magnet 340 energizes and deenergizes under control of impulsing relay 325, it advances the switch wipers 350, 351, 352, and 353 in a forward direc-.

tion over their associated bank contacts.

From the foregoing it will be seen that the transmitter T and the receiver 'R2 operate in synchronism to rotate their wipers the same number of steps. In the transmitter T when the ture 517, upper trunk conductor 233, armature 281 and its front contact, armature 291 and its back contact, conductor 288 to Fig. 3, wiper 350 and its first bank contact on which it is now resting, conductor 450 to Fig. 4, through the winding of relay 400 to battery. Relay 400 is in the digit storage relaygroup S-4, and is one of the relays of the first digit of the number. Relay 400 energizes and at its front contact and armature 401 looks up itself to ground which is maintained on conductor 238 extending back through Fig. 3, through the front contact and armature 302 of relay 300 to ground. When wiper 665 of the transmitter T reaches the third bank contact to which conductor 772 is attached, another ground pulse will be received from relay 820 of Fig. 8jand this will be transmitted over the previously traced circuit over the trunk conductor 233 to wiper 350 and its third bank contact, conductor 452, through the of relay 420 to battery. Relay 420 energizes, and at its front contact and armature 421 locks itself up to grounded conductor 238. Relay 400 and relay 420 are, therefore, held energized and at their armatures illuminate the lamp number 2, over a circuit extending from ground on armature 402 and its front contact, armature 412 and its back contact, armature 422 and its front contact, through the lamp 2, to battery. By referring to the code chart diagram of Fig. 13, it will be understood how other numerals may be displayed.

The receiver R-2 and the transmitter T continue to advance their wipers under the synchronous operation of both rotary stepping magnets, and each time the wiper 665 encounters bank contacts upon which the remaining conductors 776,

777, and 782 are connected, ground will be fed over these conductors-from the digit storage relay group DS-l, through the wiper 665 and thence over the upper trunk conductor 233, to the wiper 350, and as wiper 350 passes over its bank contacts, the conductors 455 and. 456 will each be grounded in turn, resulting in the energization of relays 465 and 470 of the group S5, which upon energizing, will display the numeral 4 over a circuit from ground at armature 466 and its back contact, armature 467 and its front contact, armature 468 and its front contact, through the lamp 4 to battery. When the wiper 350 grounds the bank contact upon which conductor 460 is connected, the relay 4800f the group S6 operates and locks to the ground on conductor 238 and displays the numeral 9, over a circuit extending from ground at armature 482 and its back contact, armature 483 and its back contact, armature 484 and its front contact, armature 485 and its back contact, through the lamp 9 to battery.

The complete number of the operated fire station FS249 has now been displayed at all the district stations. This numeral has been displayed only once on the lamp panels at the district stations and as a double precaution and to take care of any errors that may be in the equipment and that might exist, it is transmitted a second time an another lamp panel. This takes place in a manner similar to that in which sender SN transmitted the number twice to the receiver R1 of Fig. 7, and displayed it at the supervisors oflice on two separate lamp panels.

When the wiper 352 reaches the bank contact 354, it will pick up the ground multipled through all the remaining contacts, through the wiper 352, through the winding of slow-release relay 335, to battery. Relay 335 energizes and at its front contact and armature 337 places ground through the winding of relay 330 to battery. Relay 330 energizes and operates its armatures 331 and 332 to cut ofi the original energizing circuit for stepping magnet 340. At armature 336 and its front contact relay 335 prepares a circuit which is without effect at this time because the wiper 351 is rotating away from its bank contacts. At front contact and armature 338 relay 335 completes another circuit for the stepping magnet 340 which extends from the grounded bank contact over which wiper 352 is now traveling, through the front contact and armature 338, back contact and armature 341, through the winding of the stepping magnet 340, to battery. When magnet 340 energizes it opens its own circuit at armature 341 so that it energizes and deenergizes as long as there is ground on the wiper 352. When this wiper reaches its last bank contact, ground will no longer be present. Accordingly, the stepping operation is stopped and relay 335 slowly deenergizes and opens the circuit of relay 330 at its front contact and armature 337. When this relay restores its armatures 331 and 332, it places the stepping circuit in condition to again receive impulses by way of the relay 325 from its grounded armature 326. At thistime the wipers 350 and 352 are stationed on their last bank contacts, while wipers 351 and 353 are positioned opposite their first set of bank contacts. The wiper 351 is now in a position to receive the grounded impulses from the digit storage relay group DS1 over the trunk conductor in place of the wiper 350.

In the transmitter T of Fig. 6, a similar action has taken place. Wiper 666 upon reaching its bank contact 668 will find ground on this bank contact, which is multipled through all the remaining bank contacts, and extend this ground through itsown wiper 666, through the winding of slow-release relay 620, to battery. Relay 620 energizes and at its front contact and armature 621 places ground through the winding of relay 625 to battery. Relay 625 upon operating, opens the armatures 627 and 628 from their back contacts, interrupting the circuit for relay 630 and the stepping magnet 650. Relay 620 operates its armatures 623 and 624 without effect at this time, due to the fact that wiper 667 is now rotating away from its set of bank contacts. At front contact and armature 622, however, it completes a circuit extending from the grounded bank contact 668, wiper 666, front contact and armature 626, back contact and armature 661, front contact and armature 622, then through the winding of the stepping magnet 660, to battery. The stepping magnet energizes and opens its armature 661 to break its own circuit. Accordingly, the stepping magnet energizes and deenergizes, as long as there is ground through the bank contact over which wiper 666 is operating. When the wiper reaches its bank contact 669 which is not grounded, relay 620 has its circuit open and it slowly falls away. At armature 621 it interrupts the circuit of relay 625 which thereupon releases its armatures. Relay 630 is, therefore, again energized as it has been originally over a circuit extending from battery through the winding of this relay, 'back contact and armature 627, armature 661 and its back contact, armature 626 and its back contact, armature 636 and its front contact, to conductor 549 which it will be remembered extended to ground on front contact and armature 1011 of relay 1010 in Fig. 10. Relay 630, therefore, again energizes and at its front contact and armature 631 completes the circuit for the stepping magnet 660, and this in turn upon operating at its armature 661 interrupts the circuit for the relay 630. This action continues as the wiper 665 is again rotated over the bank contacts to which it has access, and as the groi'ind has remained on the conductors 770, 772, 776, 777,-

and 782 extending from the operated digit storage relay group DS-Lthis ground will be again sent over the wiper 665, the upper trunk conductor 233, then over conductor 288 to the wiper 351. A branch of the circuit from ground on armature 631 extends over conductors 550, 234 and 228 to relay 325, so that this relay controls stepping magnet 340 to step the wipers of'the receiver R-2 as before in synchronism with the transmitter T.

The bank contacts of the wiper 351 are connected to conductors leading to a group of digit storage relays DS-4 which are an exact duplicate of that shown in Fig. 4, and these various conductors are grounded from wiper 665 in a similar manner as were the conductors to which wiper 350 had access. Accordingly, the numeral 249 is displayed by these relays on the lamp panel DS-4 which is a duplicate of the first one. During this time, the number 249 of the operated fire alarm box remains displayed on the lamp panel 

